Like, for instance, how to make a bad guy’s body go away by dissolving the corpse. And she’s not loathe to use them as she searches for her husband Tom’s killers. However, she may not be as skillful in evading suspicion for her illegal deeds as her unwitting mentor.

In an exclusive sneak peek of Wednesday night's episode, NYPD Detective Singleton (Evan Parke) makes it clear he knows Keen is responsible for the murder of the aforementioned villain. But the cop’s visit to Liz isn’t totally in vain—Singleton brings Tom’s effects and, among them, his widow finds a major clue about the investigation that Tom was undertaking when he was killed.

Watch the full clip below:

Also on the episode: When a batch of bodies are found in the woods, Red points the FBI Task Force towards The Invisible Hand, a vigilante group that targets folks who commit acts that may not be illegal but are morally reprehensible.